Is Number of Subarrays with Bounded Maximum easy or hard?

The problem is rated Medium because the brute-force idea is simple but inefficient. Recognizing the transformation using count(max ≤ bound) requires deeper insight into subarray counting and inclusion–exclusion techniques.

Number of Subarrays with Bounded Maximum Python/Java solution

Python and Java implementations typically follow the same logic: implement a helper function that counts subarrays where the maximum value is ≤ a bound, then compute count(right) − count(left − 1). Both versions run in O(n) time and O(1) extra space.

How to solve Number of Subarrays with Bounded Maximum in O(n)?

Use a counting helper that tracks the number of subarrays where the maximum value is ≤ a given bound. When the current element is within the bound, extend the current valid segment and add its length to the result. When the element exceeds the bound, reset the segment length. The final result equals count(right) − count(left − 1).

What is the best approach for Number of Subarrays with Bounded Maximum?

The most efficient approach counts subarrays whose maximum value is ≤ a bound. Compute count(max ≤ right) and subtract count(max ≤ left − 1). Each count is calculated with a single linear scan, resulting in O(n) time and O(1) space. This transformation avoids checking every possible subarray.

Is Number of Subarrays with Bounded Maximum asked at Google/Amazon/Meta?

This problem represents a common array and sliding window counting pattern frequently seen in interviews at companies like Amazon, Google, and Meta. Interviewers use it to evaluate reasoning about subarrays, boundary conditions, and linear-time optimizations.

What data structure is used in Number of Subarrays with Bounded Maximum?

The solution primarily uses simple variables while iterating through an array. The algorithm relies on counting segments and two-pointer style reasoning rather than complex data structures, which keeps space usage constant.

What is the time complexity of Number of Subarrays with Bounded Maximum?

The optimal solution runs in O(n) time because the array is scanned once while maintaining a running count of valid segments. Space complexity is O(1) since only a few integer variables are stored during the scan.

Description Solution Video 32:15

795. Number of Subarrays with Bounded Maximum

Medium55.4% acceptance4 companies

Given an integer array nums and two integers left and right, return the number of contiguous non-empty subarrays such that the value of the maximum array element in that subarray is in the range [left, right].

The test cases are generated so that the answer will fit in a 32-bit integer.

Example 1:

Input: nums = [2,1,4,3], left = 2, right = 3
Output: 3
Explanation: There are three subarrays that meet the requirements: [2], [2, 1], [3].

Example 2:

Input: nums = [2,9,2,5,6], left = 2, right = 8
Output: 7

Constraints:

1 <= nums.length <= 10⁵
0 <= nums[i] <= 10⁹
0 <= left <= right <= 10⁹

Asked at 4 companies

Adobe Uber

Google Amazon

Topics

Array Two Pointers

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795. Number of Subarrays with Bounded Maximum

Asked at 4 companies

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